Expression of basement membrane components in odontogenic tumors.

OBJECTIVE: The objective was to characterize the expression of BMCs (laminins 1 and 5, collagen type IV, and fibronectin) in ameloblastomas, calcifying cystic odontogenic tumors (CCOTs), and adenomatoid odontogenic tumors (AOTs). STUDY DESIGN: BMCs were analyzed in 14 ameloblastomas, 7 CCOTs, and 7 AOTs using immunohistochemistry. RESULTS: In normal oral mucosa, linear deposits of these proteins were found at the epithelial-mesenchymal junction, but not in epithelial cytoplasm. In all tumors studied, linear deposits of all proteins were found at the epithelial-mesenchymal junction; laminin 1 was expressed in all tumor cells, regardless of cell types. For CCOTs, laminin 5 was found faintly in suprabasal cells, but expressed strongly in ghost cells. For AOTs, laminin 5 strongly decorated tumor cells adjacent to mineralization. CONCLUSIONS: Laminin 1 may be a marker for odontogenic epithelium. Additionally, laminin 5 may be involved in ghost cell formation and initiation of calcification.     

Calcifying cystic odontogenic tumor associated with other lesions: case report with cone-beam computed tomography findings

The calcifying cystic odontogenic tumor (CCOT) simultaneously occurring with other lesions at different locations in the same patient is rare. We report a patient with CCOT associated with an odontoma, a supernumerary tooth, and a dentigerous cyst simultaneously occurring in the maxilla. Cone-beam computed tomography (CBCT) images showed a well-defined expansile lesion with internal calcification, high-density masses surrounded by low-density area, and a supernumerary tooth at the anterior maxilla. Posterolaterally to these lesions, an embedded canine with pericoronal radiolucency was detected. Histopathologic examination revealed a CCOT associated with an odontoma, a supernumerary tooth, and a dentigerous cyst of the embedded canine. Enucleation was performed, and a 2-year postoperative follow-up was uneventful. CBCT was useful in giving the differential diagnosis by depicting internal calcification of CCOT, and in revealing the extent and complex relationship of these lesions.     

Effect of lead on IL–8 production and cell proliferation in human oral keratinocytes

ObjectiveTo investigate the effect of lead on the production of IL-8 and cell proliferation in normal human oral keratinocytes (NHKs).MethodsNHKs were prepared as outgrowths from normal human buccal mucosa. The cells were treated with three concentrations of lead glutamate (4.5×10^?5M, 4.5×10^?6M and 4.5×10^?7M). NHKs grown in glutamic acid were used as control. The amounts of IL-8 secreted in the culture supernatants were evaluated at 12 and 24 h using enzyme-linked immunospecific assay (ELISA). Cell proliferation was determined by the MTT colorimetric assay. Three cultures were used for each experiment, and three independent experiments were performed. Analysis of variance and Duncan's multiple range tests were used for statistical analysis.ResultsAn elevation of IL-8 in culture supernatants of NHKs treated with lead at all concentrations at 12 and 24 h after exposure in a dose-dependent manner was revealed. A significant increase in cell numbers was observed only at 24 h exposed to 4.5×10^?5M lead glutamate.ConclusionsThe capacity of NHKs, to secrete IL-8, enhanced by lead glutamate, is demonstrated here. Induction of cell proliferation is revealed only after exposure to high lead concentration. The elevation of secreted IL-8 is a probable initial sign for the acute inflammatory response and may be involved in the pathogenesis of lead stomatitis.     

A retrospective study of 60 cases of salivary gland tumors in a Thai population.

Sixty cases of salivary gland tumors were diagnosed in the Oral Pathology Department, Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from 1973 to 2002. Fifty-two cases (86.7%) involved the intraoral minor salivary glands, six cases (10%) were found in the major glands, and two cases (3.3%) were intrabony. The predominance of malignant over benign tumors was evident with 68.3% being malignant and 31.7% benign. Patients ranged in age from 9 to 75 years. The female to male ratio of benign intraoral salivary gland tumors was 1.4 to 1 and of malignant types was 1.1 to 1. The principle site of occurrence was the palate (65.4%), followed by buccal mucosa (13.5%). Pleomorphic adenoma (30%) was the most common benign tumor, and mucoepidermoid carcinoma (44.3%) was the most common malignant tumor. Comparing the data from the present study with other series, some discrepancies exist.     

Scatter factor regulation of integrin expression and function on oral epithelial cells

Integrin receptors and the growth factor, scatter factor (SF; also known as hepatocyte growth factor) have been shown to modulate similar cellular processes including embryogenesis, wound healing and tumour invasion. The purpose of this study was to examine the role of SF in the regulation of integrin expression, migration and adhesion in normal human oral keratinocytes (NHK). Integrin expression was examined using flow cytometry, SF did not alter levels of expression but had a dramatic effect on cell morphology, inducing migratory filopodia and lamellipodia. SF selectively induced migration towards fibronectin, but not towards collagen I. Integrin function was further investigated by measuring the ability of NHK to adhere and migrate on various integrin ligands. SF reduced adhesion of NHK to collagen types I and IV, laminins 1 and 5 and fibronectin. The inclusion of function-blocking antibodies revealed that SF mediated upregulation of migration through alpha(5)beta(1) integrin and downregulation of adhesion through alpha(v) integrins. SF increased tyrosine phosphorylation of FAK protein in NHK after a 30-min treatment. These results show that SF can affect keratinocyte behaviour by modifying integrin function but not expression.     

The effects of moderate hypothermia on energy metabolism and serum inflammatory markers during laparotomy

The objective of this study was to investigate energy metabolism of the gut and liver as well as serum inflammatory cytokines following exploratory laparotomy at moderate hypothermia. Two groups of rats were studied, (n=6–8/group); laparotomy at normothermia for 120 min and laparotomy at hypothermia (32–33°C) for 120 min. Study 1: Intestinal glucose, succinate, lactate, phosphocreatine, and ATP as well as hepatic glucose, succinate, lactate, and ATP were measured in terms of micromole per gram using magnetic resonance spectroscopy. Study 2: Serum levels of TNF-α, IL-1β, LPS-inducible chemokine (LIX), and sICAM-1 were measured by ELISA. Histology of the gut and liver were interpreted. Data are expressed as mean and SEM. In Study 1, laparotomy at hypothermia caused an increase in intestinal glucose levels (0.78±0.03 vs. 1.29±0.11, P=0.0012) with a decrease in hepatic lactate levels (0.82±0.04 vs. 0.44±0.06, P<0.001). There were no differences in the other metabolites between the two groups. In Study 2, there were no differences in serum TNF-α, IL-1β, LIX, or sICAM-1 between the two groups. Histological features of the gut and liver among groups were comparable. In conclusion, the intestine and liver react to hypothermia differently. However, levels of high-energy phosphates in both organs are not affected by hypothermia suggesting adequate energy for the organs. It is unlikely that hypothermia induces either systemic inflammatory response or hypoxic damage to the intestine and liver in this model.     

Potential Role of Epstein–Barr Virus in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Scoping Review

Though the oral cavity is anatomically proximate to the nasal cavity and acts as a key reservoir of EBV habitation and transmission, it is still unclear whether EBV plays a significant role in oral carcinogenesis. Many studies have detected EBV DNA in tissues and exfoliated cells from OSCC patients. However, very few studies have investigated the expression of functional EBV proteins implicated in its oncogenicity. The most studied are latent membrane protein 1 (LMP-1), a protein associated with the activation of signalling pathways; EBV determined nuclear antigen (EBNA)-1, a protein involved in the regulation of gene expression; and EBV-encoded small non-polyadenylated RNA (EBER)-2. LMP-1 is considered the major oncoprotein, and overexpression of LMP-1 observed in OSCC indicates that this molecule might play a significant role in oral carcinogenesis. Although numerous studies have detected EBV DNA and proteins from OSCC and oral potentially malignant disorders, heterogeneity in methodologies has led to discrepant results, hindering interpretation. Elucidating the exact functions of EBV and its proteins when expressed is vital in establishing the role of viruses in oral oncogenesis. This review summarises the current evidence on the potential role of EBV in oral oncogenesis and discusses the implications as well as recommendations for future research.     

Cannabinoid receptor 1 (CB1R) expression in rat dental pulp

Purpose of the researchAccumulating evidence supports the role of the cannabinoid system in providing an antinociceptive effect in various painful conditions. This effect is mediated through the Cannabinoid receptor 1 (CB1R) expressed on nociceptive afferent nerve terminals. To investigate whether this receptor plays a similar role in dental pain, we studied the presence and distribution of CB1R in rat dental pulp. Pulps from 28 maxillary molars were immunohistochemically stained with an antibody against CB1R.Principal resultsOf all tooth specimens, CB1R immunoreactivity (CB1R-ir) was observed to be associated with nerve fibers in radicular pulp and was seen as a continuous network in the subodontoblastic layer.Major conclusionCB1R was present on nerve fibers in rat dental pulp and possibly plays a role in dental pain mechanisms.     

Antiemetic effect of ondansetron 0.2 mg mL-1 in PCA morphine solution

BACKGROUND AND OBJECTIVES: To study the effect of 0.2 mg mL-1 of ondansetron added to morphine patient-controlled analgesia solution after a 4 mg loading dose on the incidence and severity of postoperative nausea and vomiting. METHODS: One hundred and sixty patients scheduled for elective surgery, between 18 and 65 yr old, were studied. Patients who smoked, received antiemetics and hormonal therapy, had a history of motion sickness or gastrointestinal disease, a body mass index >35 or menstruation at the time of the study were excluded. Patients were assigned to the ondansetron and control groups by block randomization. At the end of anaesthesia, all patients received 4 mg of ondansetron intravenously and the same patient-controlled analgesia regimen of morphine. The ondansetron group (n = 80) received 0.2 mg of ondansetron per 1 mg of morphine. The nausea score, vomiting score and the requested ondansetron dose were evaluated at 1, 2, 6, 12 and 24 h. Patient-satisfaction for nausea/vomiting was recorded at the end of the study. RESULTS: Patient characteristics and cumulative morphine consumption were similar but ondansetron group had higher pain scores (P = 0.006). The ondansetron group had a lower nausea and vomiting scores, and more patients were free from nausea and vomiting than the control group (41 vs. 26, respectively, P = 0.025). The ondansetron group had fewer cumulative ondansetron doses than the control group and better patient satisfaction than the control group (P < 0.05).CONCLUSION(S): Ondansetron 4 mg plus 0.2 mg mL-1 given with PCA morphine can reduce nausea and vomiting thus improving patient satisfaction.